Hardening technology of hard seal pneumatic ball valve and modified design of seal seat The balls of pneumatic ball valves are generally machined with 1Cr18Ni9Ti and 2Cr13. Their surface hardness differs by about HB217, which is not only easy to be damaged in working conditions, but also easy to be damaged during assembly or testing. We have used the method of supercooled extrusion to improve its surface hardness, and also used the method of gas liquid nitriding, chromium plating, amorphous nickel phosphorus plating, etc., but the effect and benefit are not ideal. Since last year, we have used the solid chromizing process for experiments. After one year of practical tests, the effect is very good. After chromizing, the surface hardness of 2Cr13 and 1Cr18Ni9Ti is over HV1000 degrees. After chromizing, the surface chromium content of carbon steel ball is up to 60-80 percent. Through the hanging piece experiment of the research institute, its corrosion resistance in seawater, nitric acid, acetic acid and other media exceeds that of 1Cr18Ni9Ti and 2Cr13 without chromizing. After the trial operation of 50 sets of Q41F-16C DN50 pneumatic ball valves, our factory has received good feedback from users. Our factory has determined to fully use them in cast iron and cast steel pneumatic ball valves to replace the original 2Cr13 extremely low manufacturing ball valves and gradually expand them to stainless steel pneumatic ball valves to achieve the goal of both improving quality and reducing cost.

Fireproof structure: according to the working conditions and user needs, the ball valve can be designed as a fireproof structure. The fire resistance design of the ball valve shall comply with the provisions of API607, JB/T6899 and other standards. Once the soft seal ring is burned due to fire, the fire protection structure of the ball valve can prevent a large amount of leakage of media and prevent further expansion of the fire.